(LifeScript Health News) Smoking doobies in your younger years may lead to schizophrenia. A recent study shows that daily marijuana use, particularly as a young adult, may impair a person’s memory and cause symptoms of schizophrenia, which include delusions, auditory hallucinations or impaired social cognition. The study, published in the July issue of Archives of General Psychiatry, also found that people with schizophrenia have a less active neurotransmitter, which is critical to working memory, and that smoking marijuana made it worse. In the University of Pittsburgh School of Medicine study, researchers examined specimens of brain tissue collected post-mortem from 23 people with schizophrenia and 23 normal subjects.